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Perception 2. Jeanette Bautista. Papers. Perceptual enhancement: text or diagrams? Why a Diagram is (Sometimes) Worth Ten Thousand Words Larkin, J. and Simon, H.A Structural object perception: 2D or 3D? Diagrams based on structural object perception Ware, C. and Irani, P.
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Perception 2 Jeanette Bautista
Papers • Perceptual enhancement: text or diagrams? • Why a Diagram is (Sometimes) Worth Ten Thousand Words Larkin, J. and Simon, H.A • Structural object perception: 2D or 3D? • Diagrams based on structural object perception Ware, C. and Irani, P. • Preattentive processing: texture and color? • Large Datasets at a Glance: Combining Textures and Colors in Scientific Visualization Healey, C. and Enns, J.
“Why a Diagram is (Sometimes) Worth Ten Thousand Words" Jill H. Larkin, Herbert A. Simon. Cognitive Science, Vol. 11, No. 1, pp. 65-99, 1987.
2 different representations Which is better? • Sentential • Sequential, like propositions in a text, • Diagrammatic • Indexed by location in a plane
Better representation? “Better” • Informational equivalence • All information in one is also inferable from the other, and vice versa • Computational equivalence • informationally equivalent plus any inference in one is just as easy and fast as the same inference in the other.
Better representation? “Representation” • Data Structures • Single sequence or indexed 2-dimentional • Attention Management • Determines what portion of the data structure is currently attended to • Programs • Processes: Search, recognition, inference
Processes • Search • Operates on the data, seeking to locate sets of elements that satisfy the conditions of one or more productions • Recognition • Matches the condition of elements of a production to data elements located through search • Inference • Executes the associated action to add new elements in the data structure
Note • Human recognition is dependent on particular representations which match processes that the person is already familiar with.
Example 1 • Pulley Problem Natural Language statement We have 3 pulleys, two weights, and some ropes, arranged as follows: • 1st weight is suspended from the left end of a rope over pulley A. The right end of this rope is attached to, and partially supports, the second weight • Pulley A is suspended from the left end of the rope that runs over pulley B, and under Pulley C. Pulley B is suspended from the ceiling. The right end of the rope that runs over pulley C is attached to the ceiling. • Pulley C is attached to the second weight, supporting it jointly with the right end of the first rope. The pulleys and ropes are weightless; the pulleys are frictionless; and the rope segments are all vertical, except where they run over or under the pulley wheels. Find the ratio of the second to the first weight, if the system is in equilibrium.
Example 1 - Sentential Data Structure
Example 1 - Sentential Program: Inference Rules
Example 1 – Sentential Inference Rules “Translated” • Because weight W1 (value 1) hangs from rope Rp and no other rope, the value associated with Rp is 1 • Because Rp and Rq pass over the same pulley, the value of Rq is 1 • Because Rp (value 1) and Rq pass over the same pulley, the value Rq is 1 • Because Rx (value 2) and Ry pass over the same pulley, the value of Ry is 2 • Because Ry (value 2) and Rz pass under the same pulley, the value of Rz is 2 • Because Ry and Rz have values 2, and the pulley Pc which they pass is supported by Rs, the value associated with Rs is 2+2=4. • Because weight W2 is supported by rope Rq (value 1) and rope Rs (value 4) and no other ropes, its value is 1 + 4 =5
Example 1 • Physics Pulley Problem • Diagrammatic representation required less search
Example 2 • Geometry problem • Significant problems in sentential representation: • Search for matching conditions • Recognition for conditions of inference rule • The original given statement does not include elements that can be recognized by the inference rules in the given problem
Example 2 • Advantages in diagrammatic: • Perceptual enhancement of the data structure • Computational difference in recognition • Considerable search differences
Benefits of diagrammatic over sentential • Can group together all information that is used together • Use location to group information about a single element • Automatically support a large number of perceptual inferences • Perceptually enhanced data structures are easier to comprehend.
Conclusion • diagrammatic representations: • reduce search • primary difference: dramatically reduce the recognition process. • once the search and recognition processes have taken place, the process of inferencing requires approximately the same level of resources.
Evaluation • Strengths • Convincing • No ambiguity in what authors are trying to prove • Sets criteria for evaluating representations through tasks • Weaknesses • Barely a mention of the “User Study” • Examples are very detailed, an overview would have been fine
Diagramming information structures using 3D perceptual primitives Pourang Irani and Colin Ware. ACM Transactions on Computer Human-Interaction. 10(1): 1-19 (2003)
3D primitives • Will drawing three-dimensional shaded elements instead of using simple lines and outlines result in diagrams that are easier to interpret?
Theories of object perception • Image-based theories: • Emphasizes the properties of visual images • Suggests that we recognize objects based on the similarities of the image they present with the images of previously viewed objects • Structure-based theories • Emphasizes viewpoint independent analysis of object structure
Applying theory to diagrams Rules of the Geon Diagram • G1: Major entities of a system should be presented using simple 3D • shape primitives (geons). • G2: The links between entities can be represented by the connections • between geons. Thus the geon structural skeleton represents the • data structure. • G3: Minor subcomponents are represented as geon appendices, small • geon components attached to larger geons. Mapping object importance • to object size seems intuitive. • G4: Geons should be shaded to make their 3D shape clearly visible. • G5: Secondary attributes of entities and relationships are represented • by geon color and texture and by symbols mapped onto the surfaces • of geons.
Applying theory to diagrams Layout Rules Geon toolkit developed to draw geons • L1: All geons should be visible from the chosen • viewpoint. • L2: Junctions between geons should be made • clearly visible. • L3: The geon diagram should be laid out • predominantly in the plane orthogonal to the view • direction.
Experiments • 5 experiments • Note: to see if it is better than node-link diagrams in general, not UML • 3 experiments: geons vs UML • 2 experiments: geons vs 2D version • Testing Search and Recognition
Experiment 1 • Substructure identification • Method • Subjects were first shown a substructure and later asked to identify its presence or absence in a series of diagrams • Results • Conclusion • Geon diagrams are easier and faster to interpret than UML diagrams
Experiment 2 • Recall of Geon versus UML diagrams • Method • 2 sets of students in Sr level CS • Set of diagrams shown at the beginning of lecture, then full set presented 50 minutes later. • Results • Conclusion • Geon diagrams are easier to remember • Geon diagrams 18% error rate vs UML 39% • 35 subjects: • 26 recalled correctly more Geon than UML • 5 recalled correctly same number • 4 recalled correctly more UML
Experiment 3 • Recall of Geon versus UML diagrams without surface attributes • Method • Same as Experiment 2 • Results • Conclusion • Strongly supports the hypothesis that remembering geon diagrams is easier than remembering UML diagrams even when not presented with surface attributes • Geon diagrams 22.5% error rate vs UML 42% • 35 subjects: • 25 recalled correctly more Geon than UML2 recalled correctly same number • 8 recalled correctly more UML
Geons vs UML • Supports idea that geons are easier to interpret and remember than UML, but this cannot be generalized • Too many differences between goens and UML to conclude that results are due to 3D primitives • Test with a direct translation to 2D
Experiment 4 • Substructure identification with Geon vs 2D sillhouette diagrams • Method • Identical to Experiment 1 • Results • Conclusion • Geon diagrams are easier and faster to interpret than 2D silhouette diagrams
Experiment 5 • Recall of Geon vs 2D Silhouette • Method • Identical to Experiments 2 and 3 • Results • Conclusion • Remembering geon diagrams is easier than their equivalent 2D silhouette diagrams • Geon diagrams 21.7% error rate vs 2D 31.2% • 34 subjects: • 25 recalled correctly more Geon than 2D • 4 recalled correctly same number • 5 recalled correctly more 2D
Problems • May not be as compact • Not as good if information structure is large • Text on a 3D area? • May be optimal for search (exp 1 and 4) • What about recognition (exp 2, 3 and 5), if important text that cannot be represented by surface attributes?
Evaluation • Strengths • Addressed issues from previous paper (2001) • Well-done user experiments • Doesn’t claim to be implying a new UML, but a general idea of node-link diagrams • Weaknesses • Description of geon theory • Diagram in 2001 paper was removed • B&W diagrams
Large Datasets at a Glance: Combining Textures and Colors in Scientific Visualization Christopher G. Healey and James T. Enns. IEEE Transactions on Visualization and Computer Graphics 5, 2, (1999), 145-167
Problem • How to visualize multivariate data elements arrayed across an underlying height field? Simultaneous use of perceptual textures and colors
Related work • Texture and color • Extensively studied in isolation • Much less work focused on combined use of texture and color • Will color variation interfere with texture identification during visualization?
Key ideas: • Preattentive Processing • Visual Interference • Best (re)introduced with an example • Target search
Test 1 Find the red circle A B
Test 2 Find the red circle A B
Test 3 Find the red circle A B
Multicolored Pexels • Perceptual textureelements • Represents each data element • Attribute values encoded in an element are used to vary its appearance • Glyph-like